Dimethylsulfide gas transfer coefficients from algal blooms in the Southern Ocean

Air–sea dimethylsulfide (DMS) fluxes and bulk air–sea gradients were measured over the Southern Ocean in February–March 2012 during the Surface Ocean Aerosol Production (SOAP) study. The cruise encountered three distinct phytoplankton bloom regions, consisting of two blooms with moderate DMS levels, and a high biomass, dinoflagellate-dominated bloom with high seawater DMS levels (> 15 nM). Gas transfer coefficients were considerably scattered at wind speeds above 5 m/s. Bin averaging the data resulted in a linear relationship between wind speed and mean gas transfer velocity consistent with that previously observed. However, the wind-speed-binned gas transfer data distribution at all wind speeds is positively skewed. The flux and seawater DMS distributions were also positively skewed, which suggests that eddy covariance-derived gas transfer velocities are consistently influenced by additional, log-normal noise. A flux footprint analysis was conducted during a transect into the prevailing wind and through elevated DMS levels in the dinoflagellate bloom. Accounting for the temporal/spatial separation between flux and seawater concentration significantly reduces the scatter in computed transfer velocity. The SOAP gas transfer velocity data show no obvious modification of the gas transfer–wind speed relationship by biological activity or waves. This study highlights the challenges associated with eddy covariance gas transfer measurements in biologically active and heterogeneous bloom environments.

Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia)

The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

Biomonitoring of air pollutants by using lichens (Evernia prunastri) in areas between Kenitra and Mohammedia cities in Morocco.

In this study, Evernia prunastri, a lichen growing in its natural habitat in Morocco was analysed for the concentration of five heavy metals (Fe, Pb, Zn, Cu and Cr) from eleven sites between Kenitra and Mohammedia cities. The control site was Dar Essalam, an isolated area with low traffic density and dense vegetation. In the investigated areas, the concentration of heavy metals was correlated with vehicular traffic, industrial activity and urbanization. The total metal concentration was highest in Sidi Yahya, followed by Mohammedia and Bouznika. The coefficient of variation was higher for Pb and lower for Cu, Zn and Fe. The concentrations of most heavy metals in the thalli differed significantly between sites (p<0.01). Principal component analysis (PCA) revealed a significant correlation between heavy metal accumulation and atmospheric purity index. This study demonstrated also that the factors most strongly affecting the lichen flora were traffic density, the petroleum industry and paper factories in these areas. Overall, these results suggest that the index of atmospheric purity and assessment of heavy metals in lichen thalli are good indicators of the air quality at the studied sites.

Human Papillomavirus and Oral Cancer: the International Agency for Research on Cancer Multicenter Study

Background: Human papillomavirus (HPV), the causal agent of cervical cancer, appears to be involved in the etiology of cancer of the oral cavity and oropharynx. To investigate these associations, we conducted a multicenter case-control study of cancer of the oral cavity and oropharynx in nine countries. Methods: We recruited 1670 case patients (1415 with cancer of the oral cavity and 255 with cancer of the oropharynx) and 1732 control subjects and obtained an interview, oral exfoliated cells, and blood from all participants and fresh biopsy specimens from case patients. HPV DNA was detected by polymerase chain reaction (PCR). Antibodies against HPV16 L1, E6, and E7 proteins in plasma were detected with enzyme-linked immunosorbent assays. Multivariable models were used for case-control and case-case comparisons. Results: HPV DNA was detected in biopsy specimens of 3.9% (95% confidence interval [CI]=2.5% to 5.3%) of 766 cancers of the oral cavity with valid PCR results and 18.3% (95% CI=12.0% to 24.7%) of 142 cancers of the oropharynx (oropharynx and tonsil combined) with valid PCR results. HPV DNA in cancer biopsy specimens was detected less frequently among tobacco smokers and paan chewers and more frequently among subjects who reported more than one sexual partner or who practiced oral sex. HPV16 DNA was found in 94.7% of HPV DNA-positive case patients. HPV DNA in exfoliated cells was not associated with cancer risk or with HPV DNA detection in biopsy specimens. Antibodies against HPV16 L1 were associated with risk for cancers of the oral cavity (odds ratio [OR]=1.5, 95% CI=1.1 to 2.1) and the oropharynx (OR=3.5, 95% CI=2.1 to 5.9). Antibodies against HPV16 E6 or E7 were also associated with risk for cancers of the oral cavity (OR=2.9, 95% CI=1.7 to 4.8) and the oropharynx (OR=9.2, 95% CI=4.8 to 17.7). Conclusions: HPV appears to play an etiologic role in many cancers of the oropharynx and possibly a small subgroup of cancers of the oral cavity. The most common HPV type in genital cancers (HPV16) was also the most common in these tumors. The mechanism of transmission of HPV to the oral cavity warrants further investigation.

Description and search labor for information retrieval

Selection power is taken as the fundamental value for information retrieval systems. Selection power is regarded as produced by selection labor, which itself separates historically into description and search labor. As forms of mental labor, description and search labor participate in the conditions for labor and for mental labor. Concepts and distinctions applicable to physical and mental labor are indicated, introducing the necessity of labor for survival, the idea of technology as a human construction, and the possibility of the transfer of human labor to technology. Distinctions specific to mental labor, particular between semantic and syntactic labor, are introduced. Description labor is exemplified by cataloging, classification, and database description, can be more formally understood as the labor involved in the transformation of objects for description into searchable descriptions, and is also understood to include interpretation. The costs of description labor are discussed. Search labor is conceived as the labor expended in searching systems. For both description and search labor, there has been a progressive reduction in direct human labor, with its syntactic aspects transferred to technology, effectively compelled by the high relative costs of direct human labor compared to machine processes.

Galactic Edge Clouds I. Molecular Line Observations and Chemical Modelling of Edge Cloud 2

Edge Cloud 2 (EC2) is a molecular cloud, about 35 pc in size, with one of the largest galactocentric distances known to exist in the Milky Way. We present observations of a peak CO emission region in the cloud and use these to determine its physical characteristics. We calculate a gas temperature of 20 K and a density of n(H2)~10^4 cm-3. Based on our CO maps, we estimate the mass of EC2 at around 10^4 Msolar and continuum observations suggest a dust-to-gas mass ratio as low as 0.001. Chemical models have been developed to reproduce the abundances in EC2, and they indicate that heavy element abundances may be reduced by a factor of 5 relative to the solar neighborhood (similar to dwarf irregular galaxies and damped Lya systems), very low extinction (A_V <4 mag) due to a very low dust-to-gas mass ratio, an enhanced cosmic-ray ionization rate, and a higher UV field compared to local interstellar values. The reduced abundances may be attributed to the low level of star formation in this region and are probably also related to the continuing infall of primordial (or low-metallicity) halo gas since the Milky Way formed. Finally, we note that shocks from the old supernova remnant GSH 138-01-94 may have determined the morphology and dynamics of EC2.

The "Art" of Criticism: Rubén Darío and his Unknown Chronicles of the 1895 Salon for "La Prensa"

With the impetus that has led recent studies on Latin American Modernism to a reevaluation of the sense of cultural fluxes from the modernity capitals to its peripheries –discarding categories such as “influence”, “exotism” and “ivory tower”, stereotypes that have clouded critical understanding of this aesthetics for decades- the present study intends to investigate a persistent practice of the main writers of the movement. This practice is modernist pictorial criticism, a genre that will be approached through the analysis of an unknown corpus: the seven chronicles Rubén Darío published in the journal La Prensa on occasion of the third art exposition of the Ateneo de Buenos Aires. Our hypothesis is that the rare creators of images portrayed by Darío by the end of 1895 work as a visual counterpoint of the eccentric writers’ biographical sketches that a year later will be part of the fundamental volume Los raros (1896). In this early “salon”, which we reproduce in its entirety, accompanied by explanatory notes, the leader of Modernism rehearses and consolidates his transcultural work with the universal tradition –now applied to the Salons (1845-1860) by Charles Baudelaire and to the monumental project by John Ruskin in Modern painters (1843-1860)- to legitimate, from another subgenre of Modernist criticism, a new figure of the critic, in dissent with the Enlightenment model of the writer.

El "Fedro" de Platón: un ejercicio de buena retórica engañosa

En este artículo me propongo mostrar que lo que Sócrates hace con Fedro a lo largo de toda la obra no es otra cosa que utilizar la auténtica retórica (con su doble carga, dialéctica y psicológica) que es descrita en la segunda parte del diálogo. Las tensiones, rivalidades y celos de la situación inicial entre ellos expone un perfil representativo de relaciones entre interlocutores con perspectivas intelectuales opuestas. Es preciso disolver la resistencia emocional por medio de una serie de pasos graduales, estratégicos, y ‘engañosos’ (no se puede develar el propio juego desde el principio). Hay que partir de acuerdos, siquiera parciales, para continuar dialogando. Sin embargo, Sócrates también introduce nociones nuevas acerca del amor, pero éstas pasan desapercibidas a un Fedro obsesionado con la imitación de su enamorado Lisias. Hasta que Sócrates decide cortar el juego y cruzar el río. Este corte provoca un giro en ambos personajes: Fedro se dispone a escuchar lo que Sócrates quiere contarle (el mito del carro alado) y Sócrates se revela ante sí mismo como un personaje capaz de ‘encantar’ a Fedro con la belleza rapsódica del relato y superar su propio temor de convertirse en una bestia devoradora. Al final Sócrates muestra su juego a Fedro y le enseña cómo ha sido posible llegar a un auténtico diálogo filosófico, donde pueda tener lugar la enseñanza y el aprendizaje recíprocos.

Cold-Atom-Induced Control of an Optomechanical Device

We consider a cavity with a vibrating end mirror and coupled to a Bose-Einstein condensate. The cavity field mediates the interplay between mirror and collective oscillations of the atomic density. We study the implications of this dynamics and the possibility of an indirect diagnostic. Our predictions can be observed in a realistic setup that is central to the current quest for mesoscopic quantumness.